fuel CHEVROLET DYNASTY 1993 Service Manual

The exhaust manifolds are made of ductile cast
iron with the front bank and rear bank independent
of each other. The exhaust from the front bank ex-
haust manifold is led through on exhaust crossover
pipe to be combined with the rear bank exhaust at
the exhaust outlet to the exhaust pipe (Fig. 2).
INTAKE PLENUM/MANIFOLD
REMOVAL
(1) Perform fuel system pressure release procedure
(before attempting any repairs). (2) Disconnect negative battery cable. Drain cooling
system. See Cooling System, Group 7. (3) Remove air cleaner to throttle body hose (Fig. 3).
FUEL SYSTEM PRESSURE RELEASE PROCE-DURE
The MPI fuel system is under a constant pres-
sure of about 330 kPa (48 psi). Before servicing
the fuel pump, fuel lines, fuel filter, throttle body
or fuel injector, the fuel system pressure must be
released .
(a) Loosen fuel filler cap to release fuel tank pres-
sure. (b) Disconnect injector wiring harness from engine
harness. (c) Connect a jumper wire to ground terminal
Number 1 of the injector harness (Fig. 1) to engine
ground. (d) Connect a jumper wire to the positive terminal
Number 2 of the injector harness (Fig. 1) and touch
the battery positive post for no longer than 5 seconds.
This releases system pressure.
Fig. 1 Injector Harness Connector
Fig. 2 Intake and Exhaust ManifoldsÐ 3.0L Engine
11 - 14 EXHAUST SYSTEM AND INTAKE MANIFOLD Ä

(e) Remove jumper wires.
(f) Continue fuel system service.
(4) Remove throttle cable and transaxle kickdown
linkage (Fig. 4). (5) Remove automatic idle speed (AIS) motor and
throttle position sensor (TPS) wiring connectors from
throttle body (Fig. 5). (6) Remove vacuum hose harness from throttle body
(Fig. 5). (7) Remove PCV and Brake booster hoses from Air
Intake Plenum. (8) Remove ignition coil from intake plenum (Fig. 6).
(9) Remove wiring connectors from coolant tempera-
ture sensor (Fig. 7). (10) Remove vacuum connections from air intake
plenum vacuum connector. (11) Remove fuel hoses from fuel rail (Fig. 7).
WARNING: WRAP SHOP TOWELS AROUND HOSES
TO CATCH ANY GASOLINE SPILLAGE. (12) Remove (8) Fasteners from Air Intake Plenum
to Intake Manifold (Fig. 8). (13) Remove air intake plenum (Fig. 9).
(14) Cover intake manifold with suitable cover when
servicing. (15) Remove vacuum hoses from fuel rail and fuel
pressure regulator (Fig. 10). (16) Disconnect Fuel Injector wiring harness from
engine wiring harness (Fig. 11). (17) Remove fuel pressure regulator attaching bolts
and remove regulator from rail (Fig. 12). Be careful
not to damage the rubber injector O-rings upon
removal from the ports. (18) Remove fuel rail attaching bolts and lift fuel rail
assembly from intake manifold. (19) Separate radiator hose from thermostat hous-
ing and heater hose from heater pipe. (20) Remove (8) nut and washer assemblies and
remove intake manifold (Fig. 2).
INSPECTION
Check for:
² Damage and cracks of each section (Fig. 13).
² Clogged water passages in end cross overs.
² Check for distortion of the cylinder head mounting
surface using a straightedge and thickness gauge (Fig.
14). Refer to (Fig. 15) for Specifications.
INSTALLATION
(1) Position new intake manifold gaskets on cylinder
head and install intake (cross) manifold. (2) Install (8) nuts and washers and tighten in
several steps in order shown in (Fig. 16) to 20 N Im
(174 in. lbs.). (3) Make sure the injector holes are clean and all
plugs have been removed. (4) Lube injector O-ring with a drop of clean en-
gine oil to ease installation. (5) Put the tip of each injector into their ports.
Push the assembly into place until the injectors are
seated in the ports. (6) Install the (3) fuel rail attaching bolts and
torque to 13 N Im (115 in. lbs.).
(7) Install fuel pressure regulator onto fuel rail. In-
stall attaching bolts to intake manifold. Torque reg-
ulator nuts and bracket bolts to 10 N Im (95 in. lbs.)
(Fig. 12). (8) Install fuel supply and return tube hold-down
bolt and the vacuum crossover tube hold-down bolt
and torque to 10 N Im (95 in. lbs.).
(9) Connect fuel injector wiring harness to engine
wiring harness (Fig. 11). (10) Connect vacuum harness to fuel pressure reg-
ulator and fuel rail assembly (Fig. 10). (11) Remove covering from lower intake manifold
and clean surface. (12) Place intake manifold gaskets with beaded
sealant side up on lower manifold. Put air intake in
Fig. 3 Throttle Body Assembly 3.0L
Fig. 4 Throttle Cable Attachment
Ä EXHAUST SYSTEM AND INTAKE MANIFOLD 11 - 15

place. Install attaching fasteners (8) and tighten in
several steps in sequence shown (Fig. 17) to 13 N Im
(115 in. lbs.). (13) Connect fuel line to fuel rail (Fig. 7). Torque
hose clamps to 1 N Im (10 in. lbs.).
(14) Connect vacuum harness to air intake ple-
num. (15) Connect coolant temperature sensor electrical
connector to sensor (Fig. 7). (16) Connect PCV and brake booster supply hose
to intake plenum. (17) Connect automatic idle speed (AIS) motor and
throttle position sensor (TPS) electrical connectors
(Fig. 5). (18) Connect vacuum vapor harness to throttle
body (Fig. 5). (19) Install throttle cable and transaxle kickdown
linkage (Fig. 4). (20) Install air inlet hose assembly (Fig. 3).
(21) Install radiator to thermostat housing hose
and heater hose to heater pipe nipple. (22) Fill cooling system, see Refilling System in
Cooling, Group 7. (23) Connect negative battery cable.
(24) With the DRBII Scan Tool use ASD Fuel Sys-
tem Test to pressurize system to check for leaks.
Fig. 5 Electrical and Vacuum Connections to Throttle Body
Fig. 6 Ignition Coil Removal
Fig. 7 Coolant Temperature Sensor Electrical Connections
Fig. 8 Air Intake Plenum to Intake ManifoldAttaching Bolts
Fig. 9 Removing Air Intake Plenum
11 - 16 EXHAUST SYSTEM AND INTAKE MANIFOLD Ä

CAUTION: When using the ASD Fuel System Test,
the Auto Shutdown (ASD) relay will remain ener-
gized for 7 minutes or until the ignition switch is
turned to the OFF position, or Stop All Test is se-
lected.
Fig. 13 Check Intake (Cross) Manifold Mounting Surface
Fig. 14 Check Intake Plenum Mounting Surfaces
Fig. 10 Vacuum Connections for Fuel Rail and FuelPressure Regulator
Fig. 11 Fuel Injector Wiring Harness
Fig. 12 Fuel Pressure Regulator to Fuel Rail Assembly
Ä EXHAUST SYSTEM AND INTAKE MANIFOLD 11 - 17

(2) Attach exhaust pipe to exhaust manifold and
tighten shoulder bolt to 28 N Im (250 in. lbs.)
(3) Attach crossover pipe to exhaust manifold and
tighten bolt to 69 N Im (51 ft. lbs.)
(4) Connect heated oxygen sensor lead (Fig. 18).
(5) Install front exhaust manifold and attach ex-
haust crossover. (6) Install front manifold heat shield and tighten
attaching screws to 15 N Im (130 in. lbs.) (Fig. 2).
INTAKE/EXHAUST MANIFOLD SERVICEÐ3.3/3.8L
ENGINES
INTAKE MANIFOLD
REMOVAL
(1) Perform fuel system pressure release procedure,
Before attempting any repairs. (2) Disconnect negative battery cable. Drain cool-
ing system. Refer to Cooling System, Group 7.
FUEL SYSTEM PRESSURE RELEASE PROCE- DURE
The MPI fuel system is under a constant pressure
of about 330 kPa (48 psi). Before servicing the fuel
pump, fuel lines, fuel filter, throttle body or fuel
injector, the fuel system pressure must be released.
(a) Loosen fuel filler cap to release fuel tank pres-
sure. (b) Disconnect injector wiring harness from engine
harness.
(c) Connect a jumper wire to ground terminal Num-
ber 1 of the injector harness (Fig. 1) to engine ground.
(d) Connect a jumper wire to the positive terminal
Number 2 of the injector harness (Fig. 1) and touch
the battery positive post for no longer than 5 seconds.
This releases system pressure. (e) Remove jumper wires.
(f) Continue fuel system service.
(3) Remove air cleaner to throttle body hose assem-
bly (Fig. 2).
Fig. 20 Check Exhaust Manifold Mounting Surface
Fig. 21 Identify Exhaust Manifold Gaskets
Fig. 1 Injector Harness Connectors
Fig. 2 Throttle Body AssemblyÐ3.3/3.8L Engines
Ä EXHAUST SYSTEM AND INTAKE MANIFOLD 11 - 19

(4) Remove throttle cable (Fig. 3). Remove wiring
harness from throttle cable bracket.
(5) Remove automatic idle speed (AIS) motor and
throttle position sensor (TPS) wiring connectors from
throttle body (Fig. 4). (e) Remove jumper wires.
(f) Continue fuel system service.
(6) Remove vacuum hose harness from throttle
body (Fig. 4). (7) Remove PCV and brake booster hoses from air
intake plenum (Fig. 5). (8) Remove EGR tube flange from intake plenum
(Fig. 5). (9) Disconnect Charge Temperature Sensor electri-
cal connector. Remove vacuum harness connectors
from Intake Plenum (Fig. 5).
(10) Remove cylinder head to intake plenum strut
(Fig. 5). (11) Disconnect MAP Sensor and heated Oxygen
Sensor electrical connection. Remove the engine
mounted ground strap (Fig. 6).
Fig. 3 Throttle Cable Attachment
Fig. 4 Electrical and Vacuum Connection to Throttle Body
Fig. 5 Electrical and Vacuum Connections To IntakeManifold
Fig. 6 MAP Sensor Electrical Connector
11 - 20 EXHAUST SYSTEM AND INTAKE MANIFOLD Ä

(12) Remove the fuel hose quick connect fittings
from the fuel rail using an open end wrench to push
in on the plastic ring located on the end of the fit-
tings. Gently pull the fittings from the fuel rail (Fig.
7).
WARNING: WRAP A SHOP TOWEL AROUND
HOSES TO CATCH ANY GASOLINE SPILLAGE.
(13) Remove direct ignition system (DIS) coils and
generator bracket to intake manifold bolt (Fig. 8). (14) Remove intake manifold bolts and rotate man-
ifold back over rear valve cover (Fig. 9). (15) Cover intake manifold with suitable cover
when servicing (Fig. 10). (16) Remove vacuum harness connector from Fuel
Pressure Regulator. (17) Remove fuel tube retainer bracket screw and
fuel rail attaching bolts (Fig. 10). Spread the retainer
bracket to allow fuel tube removal clearance. (18) Remove fuel rail injector wiring clip from the
generator bracket (Fig. 11). (19) Disconnect cam sensor, coolant temperature
sensor, and engine temperature sensors. (20) Remove fuel injector wiring clip from intake
manifold water tube. (21) Remove fuel rail. Be careful not to damage
the rubber injector O-rings upon removal from their
ports (Fig. 12). (22) Remove upper radiator hose, bypass hose and
rear intake manifold hose (Fig. 13). (23) Remove intake manifold bolts. Remove intake
manifold. (24) Remove intake manifold seal retainers screws
(Fig. 14). Remove intake manifold gasket.
INSPECTION
Check for:
² Damage and cracks of each section.
Fig. 7 Quick Connect Fuel Fittings to Fuel Rail
Fig. 8 Ignition Coils
Fig. 9 Intake Manifold Bolts
Fig. 10 Fuel Rail Attaching Bolts
Ä EXHAUST SYSTEM AND INTAKE MANIFOLD 11 - 21

² Clogged water passages in end cross overs and
clogged gas passages.
INTAKE MANIFOLD
INSTALLATION
(1) Clean all surfaces of cylinder block and cylin-
der heads. (2) Place a drop (about 1/4 in. diameter) of Mopar
Silicone Rubber Adhesive Sealant or equivalent, onto
each of the fourmanifold to cylinder head gasket
corners (Fig. 15).
WARNING: INTAKE MANIFOLD GASKET IS MADE
OF VERY THIN METAL AND MAY CAUSE PER-
SONAL INJURY, HANDLE WITH CARE.
(3) Carefully install the intake manifold gasket
(Fig. 14). Tighten end seal retainer screws to 12 N Im
(105 in. lbs.) torque. (4) Install intake manifold and (8) bolts and
tighten to 1 N Im (10 in. lbs.) torque. Then retighten
bolts to 22 N Im (200 in. lbs.) torque in sequence
shown in (Fig. 13). Then retighten again to 22 N Im
(200 in. lbs.)torque. After intake manifold is in place,
inspect to make sure seals are in place. (5) Make sure the injector holes are clean and all
plugs have been removed. (6) Lube injector O-ring with a drop of clean en-
gine oil to ease installation.
Fig. 11 Fuel Injector Wiring Clip
Fig. 12 Fuel Rail Removal
Fig. 13 Intake Manifold Removal and Installation
Fig. 14 Intake Manifold Gasket
11 - 22 EXHAUST SYSTEM AND INTAKE MANIFOLD Ä

(7) Put the tip of each injector into their ports.
Push the assembly into place until the injectors are
seated in the ports (Fig. 12). (8) Install the (4) fuel rail attaching bolts and
tighten to 22 N Im (200 in. lbs.) torque (Fig. 10).
(9) Install fuel tube retaining bracket screw and
tighten to 4 N Im (35 in. lbs.) torque (Fig. 10).
(10) Reconnect cam sensor, coolant temperature
sensor and engine temperature sensors (Fig. 11). (11) Install fuel injector harness wiring clips on
the generator bracket and intake manifold water
tube (Fig. 11). (12) Connect fuel pressure regulator vacuum line.
(13) Remove covering on lower intake manifold
and clean surface. (14) Place intake manifold gasket on lower mani-
fold. Put upper manifold into place and install bolts
finger tight. (15) Install the generator bracket to intake mani-
fold bolt and the cylinder head to intake manifold
strut bolts. Do not torque.
(16) Tighten intake manifold bolts to 28 N Im (250
in. lbs.) torque in the sequence shown in (Fig. 9). (17) Tighten generator bracket to intake manifold
bolt to 54 N Im (40 ft. lbs.) torque (Fig. 8).
(18) Tighten the cylinder head to intake manifold
strut bolts to 54 N Im (40 ft. lbs.) torque (Fig. 5).
(19) Connect ground strap, MAP and heated oxy-
gen sensor electrical connectors (Fig. 6). (20) Connect charge temperature sensor electrical
connector (Fig. 5). (21) Connect vacuum harness to intake plenum
(Fig. 5). (22) Using a new gasket, connect the EGR tube
flange to the intake manifold and tighten to 22 N Im
(200 in. lbs.) torque. (23) Clip wiring harness into the hole in the throt-
tle cable bracket. (24) Connect the wiring connectors to the throttle
position sensor TPS and automatic idle speed AIS
motor (Fig. 4). (25) Connect vacuum harness to throttle body (Fig.
4). (26) Install the direct ignition system DIS coils.
Tighten fasteners to 12 N Im (105 in. lbs.) torque
(Fig. 8). (27) Lubricate the ends of the chassis fuel tubes
with 30 wt oil. Connect fuel supply and return hoses
to chassis fuel tube assembly. pull back on the quick
connect fitting to ensure complete insertion (Fig. 7).
(Refer to Fuel Hoses, Clamps and Quick Connect Fit-
tings in Group 14 Fuel Systems). (28) Install throttle cable (Fig. 3).
(29) Connect fuel injector wiring harness.
(30) Install air cleaner and hose assembly (Fig. 2).
(31) Connect negative battery cable. Fill Cooling
System. See Cooling System, Group 7. (32) With the DRBII Scan Tool use ASD Fuel Sys-
tem Test to pressurize system to check for leaks.
CAUTION: When using the ASD Fuel System Test,
the Auto Shutdown (ASD) relay will remain ener-
gized for 7 minutes or until the ignition switch is
turned to the OFF position, or Stop All Test is se-
lected.
EXHAUST MANIFOLDS
REMOVAL
(1) Raise vehicle and disconnect exhaust pipe from
rear cowl side exhaust manifold at articulated joint. (2) Separate EGR tube from rear manifold and dis-
connect Heated Oxygen Sensor lead wire (Fig. 16). (3) Remove Generator/Power Steering Support
Strut (Fig. 16). (4) Remove bolts attaching cross-over pipe to man-
ifold (Fig. 16).
Fig. 15 Intake Manifold Gasket Sealing
Fig. 16 EGR Tube, Heated Oxygen Sensor and Generator/Power Steering Strut
Ä EXHAUST SYSTEM AND INTAKE MANIFOLD 11 - 23

FUEL SYSTEMS
CONTENTS
page page
2.2L TURBO III MULTI-PORT FUEL INJECTIONÐ GENERAL DIAGNOSIS ................. 95
2.2L TURBO III MULTI-PORT FUEL INJECTIONÐ ON-BOARD DIAGNOSTICS ............. 100
2.2L TURBO III MULTI-PORT FUEL INJECTIONÐ SERVICE PROCEDURES ............... 107
2.2L TURBO III MULTI-PORT FUEL INJECTIONÐ SYSTEM OPERATION .................. 83
2.2L/2.5L SINGLE POINT FUEL INJECTIONÐ GENERAL DIAGNOSIS .................. 35
2.2L/2.5L SINGLE POINT FUEL INJECTIONÐ ON-BOARD DIAGNOSTICS .............. 41
2.2L/2.5L SINGLE POINT FUEL INJECTIONÐ SERVICE PROCEDURES ................ 48
2.2L/2.5L SINGLE POINT FUEL INJECTIONÐ SYSTEM OPERATION .................. 24
2.5L FLEXIBLE FUEL MULTI-PORT FUEL INJECTIONÐGENERAL DIAGNOSIS ....... 66
2.5L FLEXIBLE FUEL MULTI-PORT FUEL INJECTIONÐON-BOARD DIAGNOSTICS . . . 70
2.5L FLEXIBLE FUEL MULTI-PORT FUEL INJECTIONÐSERVICE PROCEDURES ..... 77
2.5L FLEXIBLE FUEL MULTI-PORT FUEL INJECTIONÐSYSTEM OPERATION ....... 55 3.0L MULTI-PORT FUEL INJECTIONÐ
GENERAL DIAGNOSIS ................. 125
3.0L MULTI-PORT FUEL INJECTIONÐ ON-BOARD DIAGNOSTICS ............. 130
3.0L MULTI-PORT FUEL INJECTIONÐ SERVICE PROCEDURES ............... 138
3.0L MULTI-PORT FUEL INJECTIONÐ SYSTEM OPERATION ................. 113
3.3L AND 3.8L MULTI-PORT FUEL INJECTIONÐ GENERAL DIAGNOSIS ................. 157
3.3L AND 3.8L MULTI-PORT FUEL INJECTIONÐ ON-BOARD DIAGNOSTICS ............. 162
3.3L AND 3.8L MULTI-PORT FUEL INJECTIONÐ SERVICE PROCEDURES ............... 169
3.3L AND 3.8L MULTI-PORT FUEL INJECTIONÐ SYSTEM OPERATION ................. 145
ACCELERATOR PEDAL AND THROTTLE CABLE .............................. 21
FUEL DELIVERY SYSTEM ................. 3
FUEL TANKS .......................... 14
GENERAL INFORMATION .................. 1
SPECIFICATIONS ...................... 178
GENERAL INFORMATION
Throughout this group, references are made to a
particular vehicle by letter designation. A chart
showing the breakdown of these designations is in-
cluded in the Introduction Section at the front of this
service manual. The Fuel System consists of the fuel tank, fuel
pump, fuel filter, throttle body, fuel injectors, fuel
tubes and vacuum tubes. The Fuel Delivery System consists of the fuel
pump, fuel filter, fuel lines and fuel hoses. The Fuel Tank Assembly consists of the fuel tank,
filler tube, a fuel gauge sending unit assembly and a
pressure-vacuum filler cap. Also, the Evaporation Control System is part of the
fuel system. The evaporation control system is de-
signed to reduce the emission of fuel vapor into the
atmosphere. The description and function of the Evaporation
Control System is found in Group 25 of this manual.FUEL REQUIREMENTS
Your vehicle was designed to meet all emission
regulations and provide excellent fuel economy when
using high quality unleaded gasoline.
VEHICLES WITHOUT TURBOCHARGED ENGINES
Use unleaded gasoline having a minimum octane
rating of 87.
VEHICLES WITH TURBOCHARGED ENGINESÐEXCEPT 16 VALVE 2.2L ENGINES
These vehicles will operate satisfactorily on both
regular unleaded gasoline having a minimum octane
rating or 87, and premium unleaded gasoline having
a minimum octane rating of 91. The use of premium
unleaded gasoline will improve performance.
VEHICLES WITH 2.2L 16 VALVE ENGINES
The use of premium unleaded gasoline having a
minimum octane of 91 is recommended. If premium
unleaded is not available, then unleaded gasoline
Ä FUEL SYSTEMS 14 - 1